Renewable fuse plug



Patented Dec. l1, 1923.

UNITED STATES 1,416,875 PATENT OFFICE.

JOHN G'. CLEMENS, OF BUFFALO, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TO EDWIN D. CAHILL, 0Fv HAMILTON, ONTARIO, CANADA.

RENEWABLE FUSE PLUG.

Application filed September -11, 1920. Serial No. 409,621.

To all whom, it may concern.'

lle it known that l, JOHN Gr. CLaMnNs, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Renewable Fuse Plugs, of which the following is a specification.

This invention relates to renewable fuse plugs and has as one of its objects to provide a plug so constructed that when the fuse is blown the generated gases will be permitted to expand andbecome somewhat cool before escaping to the atmosphere thus eliminating the noise which usually results from blowing of a fuse plug, and also preventing the discharge of flames from the lug.

Another object of the invention is to so construct the plug that the arc produced upon blowing of the fuse will not follow along the fusible element of the plug for any considerable portion of its length so there will be no likelihood of the arc burnn ing through the shell of the plug and probably causing damage to the plug socket.

Another object of the invention is to provide for maximum protection being afforded the shell of the plug to prevent the shell being burned through at the time of burning of the fuse.

A further object of the invention is' to provide a plug the fusible element of which may be`readily renewed whenever required.

In the accompanying drawings:

Figure 1 is a perspective view illustrating the plug embodying the invention, the parts being separated;

Figure 2 is a detail vertical longitudinal sectional view through the plug, all parts thereof being assembled;

Figure 3 is a erspective view `of therenewable fusible e ement.

The plug embodying the invention comprises an outer member indicated in general by the numeral 1 and an inner member indicated in general by the numeral 2. The outer member consists of a shell 3 of brass or any other suitable metal open at one end and closed at its other end as indicated by the numeral 4. From its open end, for any desired portion of its length, the shell 3 is crimped to provide threads 5 so as to adapt this end of the shell to receive the member 2 which for this purpose is likewise provided with threads 6. The outer member 1 likewise consists of a cap 7 which is of porcelain or any other suitable insulating material and which is fitted onto its closed end. The cap/ more or less snugly encompasses the closed end portion of the shell 3, and the open end portion of the shell projects beyond the open end of the cap a sufficient distance to adapt the plug as a whole to be threaded into its socket. In order to secure the shell and cap together, a metallic disk 8 is disposed within the closed end of the shell and isprovided with threaded openings 9 receiving,r the ends of screws 10 which are passed through openings 11 in the closed end of the cap and the closed end of the shell, the heads of the screws when tightened bearing against the said end of the cap. For a purpose to be presently explained a disk 12 of any suitab e insulating material is arranged within the closed end of the shell 3 and covers the face of the ldisk 8.

The inner member 2 of the plug comprises a body 13 preferably of porcelain which body is provided at its outer end withk a polygonal boss 14 whereby the body may be threaded into theI shell 3 in-assembling the two members of the plug. The body is provided at its opposite or inner end with an axially located neck 15 which is of a diameter considerably less than that of the body` and the said body and its neck 15 are formed with an axially extending bore 16 which constitutes an explosion chamber as will be presently explained, this 'bore\ opening through the end of the neck 15 and terminating short of the outer end-of the body, the said end of the body being however formed with a small opening or slot 17 communicating with the corresponding end of the chamber 16.v

The fusible element of the plug isindicated in general by the numeral 18 and, as most clearly shown in Figure 3 of the drawings, comprises a head 19 which may be of sheet metal crimped or otherwise formed to secure it to the doubled or folded end 20 of a strip of metal 21 which constitutes the fusible element proper. A washer 22 of insulating or any other suitable material is fitted onto the end portion 20 of the fusible element and, when this portion of the element is fitted through the 'opening or slot 17, lies between the outer end of the body 13 of the inner plug member and the head seid body so bet e' 19 .of 1be Jfusible eiemeiit and serves so eiose of seal the seid opening 1'? subsentisiy in an eiirigb; manner. The bead 19 constutes of course e come@ bead5 and in oideif tbes eine euiireii; may be conducted by the' fusible eiemeiis o 'die sbeii 3, tbe sbiip compiising 'tbe eiemeiit is led through @be eX 'piosion chamber 16 'so be osier enci thereof end is then bent over i-be eed of ibe iiecii: 157 :is indicated by bhe mimei'zii 239 emi bes its teiminei peii'ion seated besweeii die ifi/eli of the sbei 3 and be oui-ei' surface 'oiE 'be body 13, bis ieuiiiiiei peibionE Wbiob is inn diceied by ibe nuiiieiei 219 beiiig; eiimpeci as indicated by the nuii'ierei 25 io ii@ 'libe ihi'esds of 1f-be body 13 and sbeii 5. The crimped poiion of iisibie eieii'ieiib extends between tbe body end sbeii 3 i'eiminees sboi't of iiie oue? emi of this poi' ssves o some bhe mili die sbeii et one side from be' eoiiesponciiig side of tbe body 13, neve ibeiess the encimosi; bieecis die sbeii :im body or i` ibei woios se locate@ bejfe tbe efiiei` jy be poiiioe mi; eioseiy iii cf eci kso 'to iesiiei; this space ably seduced iii iioifi oil iis eiige tbe ebsiiibeif 1i 267 so theft Wb Wiii be foire-ed ai ix.,-

From itbe foregoing deseiiption o1"m 'Lbe in veniion 1b W111i be understood 'that when "die fusible eiemen; iT i'used, she eie' Wiii be formed Within tbe eiipiosioii ebzimbei" 16 and will be restricted to this cbeiibei1 because of 'abbe reativeiy smeii size o1 the chembei, the heated." gases geneiefeci passing from ibe chamber iniso bhe space Within the shell 3 which surrounds abe neck 15 and wbicb space constitutes en expansion chamber indicated by the immersi 2? After leaving the chembei' 16 sind ezpemiiiig Within the chamber Q79 tbe gases wiii ieeve tbe iabsei7 cheminer, passing; out m e more or iess giaci ai maniiei' bieugh the space between Weii o* 'cb 1be sbeii 3 smi the outer sui-fece J[be body 13, which space is povideci es befoi'e seed, by be presence of she poition 25 of tbe fusible element. Thus by the time ibe ieee-b tbe atmosphere they' Wiii i'imf'e banded and become cool and therefore tief is :oo noise oi iepoi't creeieci upon biowin of 'be Jfuse noi is iheie any iiieiibood o iiames "sing discharged from be ping. Tb disk 12 serves "no piofgeo be disk 8 en dosed en@ of the sbeii fiom 'die bey We (iisciiaigeci die open. of be e giosive cbembeiz w' wing ibas described Jbe iiivenien what is cisffime as new' is:

eiiewsbie'fuse ging compi'isiiig s eiosec. one emi end open t 'I ene me @soi-f e 'bieecied body f-c sebi? iiiie T ii f find ce li g fiieieby eis expansion. cbembei is piovioled. in eisec; communication with the eizpiosioii ebzimbei in libe body, and e usibie eiemeiit having one end exending iiiirough 'bbe eiosec outer emi. of ibe body and being led biougb be explosion chamber and ovei` tbe emi o tbe neck and isposed at its ober emi between the outei side of the said bodv end the W211i of the shell and in electrical come@ with the letter.

1n testimony whereof 1 six in signature.

JHN @L CLEMLN [Le] 

